Modular desk unit



FIG. 1 is a top view of a modular desk unit showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a left side elevational view as seen when in use; and,

FIG. 4 is a top front perspective view thereof.

The rear of the unit forms no part of the claimed design. 

The ornamental design for a modular desk unit, as shown and described. 